Addressing the 2008 Paydirt South Australian Resources and Energy Investment Conference in Adelaide, he said this was over 80% of the $820 million invested in Australian geothermal exploration.

"Eventually, the country is going to be wanting several or more gigawatts of this emissions-free base-load energy, and the largest part can come from South Australia," he said.

Goldstein said that the South Australian Heat Flow Anomaly offered "perfect conditions" for geothermal exploitation with temperatures of more than 200C beneath relatively shallow sedimentary cover, and rocks susceptible to the fracturing necessary for the extraction of high-pressure steam.

"Technologies are ‘off-the-shelf' for deep drilling to reach 200C. In Russia, the oil and gas industry is drilling to 11 kilometres depth, and vast parts of the world are at 200C or more at a depth of 6.5 kilometres," he said.

"If we can demonstrate ease in developing hot rocks here in Australia, the opportunities to expand around the world will be vast.

"There are plenty of opportunities in SA to provide 24-7 base-load geothermal energy for hundreds of years to come, and an expenditure currently of over $685 million in work programs proves just how confident our explorers are."

Goldstein, who also chairs the 65-member Australian Geothermal Energy Group (AGEG), said the industry aims to have heat energy flowing at 10 geothermal projects, and at least three demonstration projects generating power, by 2012.

"We would like at least one of these projects to be demonstrating a compelling level of success, so that the investment community is convinced that geothermal energy is real, by 2012."

He added the impending arrival of an emissions cap and trading scheme, and Federal renewable energy credits, will drive geothermal energy into markets as a cost-effective alternative to traditional energy sources.

"Already, federal and state governments have committed $100 million to the industry to pull hot rock technologies though its learning curves," he said.

"The Council of Australian Governments is also planning to publish a roadmap for the geothermal industry later this year."

The AGEG aims to contribute at least 7% of the national base-load demand from hot rock power by 2030 - and more than 10% by 2050.